1. Field of the Invention
The present invention relates to a derivative of alkyl 3-(substituted or unsubstituted benzylidene)-1-alkyl-2-oxocyclopentanecarboxylate, a process for preparing this compound, an antifungal composition comprising the same, and use of this compound as an intermediate for the preparation of an antifungal compound.
2. Description of Background Art
Derivatives of 2-(substituted or unsubstituted benzyl)-5-alkylcyclopentanone are described as intermediates for the manufacture of agriculture chemicals, medicines, and the like in U.S. Pat. Nos. 4,863,505, 4,938,792, and U.S. Pat. No. 5,162,356.
An improved manufacturing process of these intermediate compounds is proposed in U.S. Pat. No. 5,258,404.
Further, derivatives of 2-(substituted or unsubstituted benzylidene)-5-alkylcyclopentanone are described as intermediates of agriculture chemicals in U.S. Pat. No. 5,256,683.
The present inventors have conducted studies on a novel process for preparing derivatives of 2-(substituted or unsubstituted benzyidene)-5-alkylcyclopentanone or derivatives of 2-(substituted or unsubstituted benzyl)-5-alkylcyclopentanone, both useful as intermediates for the manufacture of valuable compounds as mentioned above, and found that either intermediate compound can be produced from derivatives of alkyl 3-(substituted or unsubstituted benzylidene)-1-alkyl-2-oxocylopentanecarboxylate, which are novel compounds, and these novel compounds are useful as an effective ingredient of an antifungal composition. These findings have led to the completion of the present invention.
The present inventors have found that derivatives of alkyl 3-(substituted or unsubstituted benzylidene)-1-alkyl-2-oxocylopentanecarboxylate of the following formula (I), ##STR2## wherein R.sup.1 and R.sup.2 individually represent a lower alkyl group; X is a halogen atom, a cyano group, an alkyl group, a haloalkyl group, a phenyl group, or a nitro group; and m is an integer of 0 to 5; provided when m is 2 or larger, Xs may be either the same or different, are compounds which can be converted into either derivatives of 2-(substituted or unsubstituted benzylidene)-5-alkylcyclopentanone the following formula (VIb) or derivatives of 2-(substituted or unsubstituted benzyl)-5-alkylcyclopentanone the following formula (VIIb), ##STR3## wherein R.sup.1, X and m are the same as defined above, and R.sup.3 b represents a hydrogen atom or a lower alkyl group.